Mesothelioma (C45) ICD-10-CM
The C45 code range covers mesothelioma with 6 ICD-10-CM diagnosis codes. 5 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.
Codes in the C45 Range 6 codes · 5 billable
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the C45 range.
Mesothelioma
A tumor derived from mesothelial tissue (peritoneum, pleura, pericardium). It appears as broad sheets of cells, with some regions containing spindle-shaped, sarcoma-like cells and other regions showing adenomatous patterns. Pleural mesotheliomas have been linked to exposure to asbestos. (Dorland, 27th ed)
Mesothelioma, Cystic
A peritoneal mesothelioma affecting mainly young females and producing cysts of variable size and number lined by a single layer of benign mesothelial cells. The disease follows a benign course and is compatible with a normal life expectancy, requiring occasionally partial excision or decompression for relief of pain or other symptoms. Malignant potential is exceptional. (From Holland et al., Cancer Medicine, 3d ed, p1345)
Mesothelioma, Malignant
A type of mesothelioma with a tendency to metastasize. Most tumors originate from either the PLEURA or PERITONEUM, tumors may also originate in the PERICARDIUM or testicular tissue. It is associated with ASBESTOS exposure. Somatic mutations identified in WT1, BCL10, CDKN2A, NF2, and BAP1 genes are associated with the malignancy. OMIM: 156240.
Solitary Fibrous Tumor, Pleural
A rare neoplasm, usually benign, derived from mesenchymal fibroblasts located in the submesothelial lining of the PLEURA. It spite of its various synonyms, it has no features of mesothelial cells and is not related to malignant MESOTHELIOMA or asbestos exposure.
About the C45 Code Range
Mesothelioma refers to a rare cancer arising from the mesothelial cells lining various body cavities. The ICD-10 code C45 and its subcodes categorize mesothelioma based on location, guiding precise diagnosis and billing.
These codes are used to specify mesothelioma when coding medical records or insurance claims. For example, C45.0 captures mesothelioma of the pleura, also known as malignant mesothelioma of pleura or primary desmoplastic mesothelioma of pleura. C45.1 covers mesothelioma of the peritoneum and related sites like the mesentery or omentum. When mesothelioma affects the pericardium, C45.2 is the correct code. Other locations such as the tunica vaginalis or overlapping retroperitoneal sites fall under C45.7. If the site is unspecified or unclear, C45.9 applies, including general terms like primary malignant mesothelioma or malignant tumor of mesothelial tissue. These precise ICD-10 codes help differentiate mesothelioma types and support accurate clinical documentation.
Questions About This Page
How many billable codes are in the C45 range?
Of the 6 codes in this range, 5 are billable and valid for claim submission from October 1, 2025 through September 30, 2026. Category header codes group them but cannot be reported on claims.
What does the C45 range classify?
The range classifies mesothelioma. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.
